1. Field of the Invention
The invention relates to fastener assemblies, and more particularly, to non-removable structural fastener assemblies for aircraft panels or the like.
2. Description of Pertinent Art
Fasteners are used in a variety of applications, wherein surfaces being connected together impose unique stringent requirements for which the fastener must particularly adapt.
The applications, in which rivets or structural fasteners are used in the construction of aircraft, impose some of the most stringent requirements. In particular, the fasteners must secure different members of the aircraft, but resist losing their clamping power under the forces and vibrations imposed upon them by the harsh environment in which they are used.
In assembling panels to the aircraft structure, alignment problems may occur where the panels are to be affixed to the aircraft body. Over the years, aircraft manufacturers have sought various solutions to this problem, such as line hole drilling the panels and body substructure. Due to the size of the panels and the quantity of the holes, the holes on the panels and substructure still get misaligned and installation of traditional fasteners offer many challenges. Therefore, there is a need of a fastener that will have the ability to align the holes drilled during installation. This will reduce the effort required to install the fasteners in the aircraft panels.
In most aircraft fastening applications, the fasteners are made substantially stronger than the strength of the joint. In most cases the joint fails (e.g. hole elongation, edge tear-out, etc.) while the fastener is still in tact. Therefore, there is a need for a fastener that better complements the strength of the joint and offers considerable weight savings sought by the aircraft industry.
It is important to achieve this goal without compromising the standards established by the aircraft industry. Such standards are set forth by industry recognized professional organizations (e.g. National Aerospace Standard (NAS)) or are established by industry leaders as Boeing Airplane Co. or Lockheed Martin.